1. Field of the Invention
The present invention relates to a gas nail gun and more specifically, to a gas can mounting structure for gas nail gun that facilitates accurate installation of a gas can, avoiding gas leakage during the installation of the gas can.
2. Description of the Related Art
FIG. 1 shows a conventional gas nail gun 10. The gas nail gun 10 comprises a gas can holder 11 that defines therein an accommodation chamber 112 for accommodating a gas can 12, a top cover 13 pivoted to the top side of the gas can holder 11 for closing the accommodation chamber 112.
When loading a gas can 12 into the accommodation chamber 12, the gas can 12 must be turned to the right angle to let the gas valve 122 of the gas can 12 be moved along an arced face 142 of a gas nozzle 14 into an air hole 144 of the gas nozzle 14, thereby completing the loading of the gas can 12. Thereafter, as shown in FIG. 2, the top cover 13 is turned downward to close the top opening of the accommodation chamber 112, as shown in FIG. 3, and then top cover 13 is forced downwards into the locking position. When pushed the bottom end of the safety rod 15 of the gas nail gun 10, the safety rod 15 is moved upwards bias the top cover 13, forcing a roller 16 that is pivotally mounted in the top cover 13 to stop against the head 124 of the gas can 12, and therefore the gas can 12 is caused to discharge fuel gas through the gas valve 122 and the air hole 144 of the gas nozzle 14 into a combustion chamber 17, completing a gas intake stroke.
According to the aforesaid design, the gas can holder 11 has no means provided in the accommodation chamber 112 to guide insertion of the gas can 12 into the accommodation chamber 112 in the accurate direction. When inserting the gas can 12 into the accommodation chamber 112, the gas valve 122 of the gas can 12 may be not kept in accurate alignment with the arched face 142 of the gas nozzle 14 for accurate insertion into the air hole 144 of the gas nozzle 14. At this time, the user must adjust the angle of the gas can 12 to have the gas valve 112 be in accurate alignment with the arched face 142 of the gas nozzle 14, complicating the installation of the gas can 12.
Further, when the gas valve 122 of the gas can 12 is inserted into the air hole 144 of the gas nozzle 14 during installation, the gas valve 122 is kept closed. When pressing the top cover 13, as shown in FIG. 2, the pivot shaft 162 of the roller 16 will be moved upwards along a sloping surface 182 of a hook 18 at the gas can holder 11 to the top side of the sloping surface 182. When continuously pressing the top cover 13, as shown in FIG. 3, the pivot shaft 162 of the roller 16 will be moved over the top side of the sloping surface 182 and then turned downwards to the hook groove 184 of the hook 18 to lock the top cover 13. However, when the pivot shaft 162 of the roller 16 is moving over the top side of the sloping surface 182, the roller 16 imparts a push force to the head 124 of the gas can 12, forcing the gas can 12 forwards (see the imaginary line in FIG. 3), causing the gas can 12 to discharge fuel gas transiently. Therefore, a certain amount of fuel gas will leak out of the gas can during each gas can installation process.